%0 Journal Article
%K Electrodes
%K Crystal structure
%K Electric properties
%K Ferroelectricity
%K Ferroelectric devices
%K Ferroelectric capacitors
%K Interfaces (materials)
%K Diffusion barrier
%K X-ray photoelectron spectroscopy
%K Chemical reactions
%K Diffusion in solids
%K Intermetallics
%K Oxidation resistance
%K Segregation (metallography)
%K High density memories
%K Titanium aluminum
%K Titanium alloys
%A S Aggarwal
%A B Nagaraj
%A I.G Jenkins
%A H Li
%A R.P Sharma
%A L Salamanca-Riba
%A Ramamoorthy Ramesh
%A A.M Dhote
%A A.R Krauss
%A O Auciello
%B Acta Materialia
%D 2000
%G eng
%P 3387-3394
%R 10.1016/S1359-6454(00)00148-8
%T Correlation between oxidation resistance and crystallinity of Ti-Al as a barrier layer for high-density memories
%V 48
%X The Ti-Al intermetallic material system has been investigated for application as a conducting diffusion barrier in a three-dimensional stacked capacitor-transistor geometry. La-Sr-Co-O (LSCO)/Pb-Zr-Ti-Nb-O/La-Sr-Co-O ferroelectric capacitors were fabricated on Ti-Al/polycrystalline-Si/Si substrates. The electrical and ferroelectric properties are found to correlate strongly with the crystallinity of the Ti-Al layer. The crystalline Ti-Al layer shows a distinct chemical reaction with the bottom LSCO electrode thus preventing ohmic electrical contact between the ferroelectric capacitor and transistor. In contrast, the amorphous Ti-Al layer does not react and forms an ohmic contact to LSCO. For crystalline Ti-Al, X-ray photoelectron spectroscopy (XPS) shows the formation of Al2O3 induced by the segregation of Al to the LSCO/Ti-Al interface. For amorphous Ti-Al, XPS reveals that no Al2O3 layer is formed. In addition, Rutherford backscattering analysis shows almost no difference in the Ti-peak spectrum before and after deposition of LSCO.